Linter for explicit/implicit returns

NEWS.md

@@ -26,7 +26,7 @@
 * `library_call_linter()` is extended
   + to encourage all packages to be attached with `library(symbol)`, not `library("symbol", character.only = TRUE)` or "vectorized" approaches looping over package names (part of #884, @MichaelChirico).
   + to discourage many consecutive calls to `suppressMessages()` or `suppressPackageStartupMessages()` (part of #884, @MichaelChirico).
-* `return_linter()` also has an argument `use_implicit_returns` (`TRUE` by default) which, when `FALSE`, forces all returns to be explicit (part of #884, @MichaelChirico and @MEO265).
+* `return_linter()` also has an argument `return_style` (`"implicit"` by default) which checks that all functions confirm to the specified return style of `"implicit"` or `"explicit"` (part of #884, @MichaelChirico, @AshesITR and @MEO265).
 * `unnecessary_lambda_linter` is extended to encourage vectorized comparisons where possible, e.g. `sapply(x, sum) > 0` instead of `sapply(x, function(x) sum(x) > 0)` (part of #884, @MichaelChirico). Toggle this behavior with argument `allow_comparison`.
 
 ### New linters

R/return_linter.R

@@ -14,7 +14,7 @@
 #' @param except Character vector of functions that are not checked when
 #'   `return_style = "explicit"`. These are in addition to namespace hook functions
 #'   that are never checked: `.onLoad()`, `.onUnload()`, `.onAttach()`, `.onDetach()`,
-#'   and `.Last.lib()`.
+#'   `.Last.lib()`, `.First()` and `.Last()`.
 #'
 #' @examples
 #' # will produce lints
@@ -74,9 +74,8 @@ return_linter <- function(
   } else {
     # See `?.onAttach`; these functions are all exclusively used for their
     #   side-effects, so implicit return is generally acceptable
-    default_except <- c(".onLoad", ".onUnload", ".onAttach", ".onDetach", ".Last.lib")
 
-    except <- union(default_except, except)
+    except <- union(special_funs, except)
 
     base_return_functions <- c(
       # Normal calls

tests/testthat/default_linter_testcode.R

@@ -25,7 +25,6 @@ g <- function(x) {
 # object_name
 # object_usage
 # open_curly
-# return
 # T_and_F_symbol
 someComplicatedFunctionWithALongCamelCaseName <- function(x)
 {